Where are all the hummingbirds?

We notice fewer hummingbirds (Ruby Throated) are around our house than previous years. We've lived here since 2005 and every spring there have been dozens of hummingbirds. By now there should be at least 10 or 12 and by the end of the summer, with the babies coming along, dozens. But we only have maybe three or four!! It is disheartening. We have the same flowers, except the previous owner did have wild flowers growing at one side of the house that I haven't planted like he did. I do have some in the rock garden, but we have all the same other things, plus all the woods around. And they came around in the previous years we've been here. I hope people respond to my poll about this issue.